1) Field of the Invention
The present invention relates to an electronic device, such as a facsimile device or a copying device, having an energy saving mode, and control method thereof.
2) Description of the Prior Art
In an electronic device, such as a facsimile device or a copying device, it is frequently conducted to provide an energy saving mode in order to reduce power consumption when the electronic device is not used. In the energy saving mode, electric power is supplied to only a minimum number of components required for a return to an ordinary mode and supply of electric power to other components is stopped.
If a request for a return to the ordinary operation is issued to an electronic device assuming the energy saving mode by using any of various sensors or key operation, then the return request is detected and a return from the energy saving mode to the ordinary mode is effected to supply electric power to respective components of the electronic device.
In recent years, there is developed an electronic device in which a request for a return to the ordinary mode from the energy saving mode is issued from a non-contact IC card. In order to attain interface (hereafter abbreviated to I/F) with the non-contact IC card, an I/F circuit is provided in a main body of the electronic device. Furthermore, if the non-contact IC card is a card that needs an external power supply, then it is necessary to supply electric power from the I/F circuit of the electronic device main body.
Since electric power is supplied from the I/F circuit of the electronic device main body to the non-contact IC card in the non-contact state by using, for example, electromagnetic induction, however, great power is consumed. This results in a problem that energy consumed at the time of the energy saving mode cannot be sufficiently suppressed. If reduction of the energy consumption is given priority, the non-contact IC card cannot be used as a factor of a request for a return from the energy saving mode, resulting in a problem.